Building up an ultralight Brompton?

Reply Subscribe

Thread Tools

Search this Thread

03-03-07 | 10:33 AM

#26

caotropheus

Senior Member

Joined: Mar 2005

Posts: 863

Likes: 0

From: Portugal-Israel

Quote:

Originally Posted by jur

On one of those threads that was lost due to server issues, someone once asked about the frame weight of a Raleigh 20.

I was

03-03-07 | 10:52 AM

#27

James H Haury

Hauja

Joined: Mar 2005

Posts: 848

Likes: 0

From: Central North Dakota

Bikes: not as many but still too many

11.4 kg

I think it is about 25 lbs.

03-06-07 | 08:26 AM

#28

adr5

Junior Member

Joined: Mar 2007

Posts: 7

Likes: 1

Quote:

Originally Posted by mingonn

Stelvios are a must then the seat if you don't mind a harsher ride. From then on it $$ per gram goes up, and up and up.

What amazes me is how much lighter comparable priced road bikes to folders. Bigger frame, longer spokes, bigger wheels, front deraileur, etc and they often weigh the same or less. Those hinges must be heavy.

It's all about stiffness. To get a decent ride a bike must not flex too much. A triangulated frame, like a standard bike, is very stiff. So you can use lighter weight materials and still get good stiffness. Most folding bikes use a single tube connecting the front end to the rear of the bike. To get good stiffness you need to make the tube pretty thick. That adds weight to the frame. The hinges will also add extra weight.